Synlett 2003(5): 0623-0626
DOI: 10.1055/s-2003-38376
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

An Interesting AlEt3-Promoted Stereoselective Tandem Rearrangement/Reduction of α-Hydroxy (or Amino) Heterocyclopropane

Xin Li, Bin Wu, Xue Zhi Zhao, Yan Xing Jia, Yong Qiang Tu*, De Run Li
Department of Chemistry & State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. China
Fax: +86(931)8912582; e-Mail: tuyq@lzu.edu.cn;
Further Information

Publication History

Received 21 January 2003
Publication Date:
28 March 2003 (online)

Abstracts

THF-inactivated AlEt3 has been found to have an interesting double reactivity: Lewis acidity and reduction activity, which can result in a novel tandem rearrangement/reduction of α-hydroxy (or amino) heterocyclopropane. On the basis of this observation, a facial and highly diastereoselective method for construction of 2-quaternary-1, 3-diheteroatom units has been developed. Three kinds of substrates have been proven to be effective for this reaction.

3

The general experimental procedure (1a as example): Under Ar protection, a solution (1.0 mL, 3.0 mmol, 3 M) of AlEt3 in THF, was added dropwise to a stirred solution of 1a (190 mg, 1.0 mmol) in 10 mL dry THF. The reaction mixture was refluxed under Ar atmosphere. After TLC analysis showed the reaction was complete, the reaction mixture was poured into aqueous HCl (2 N) at 0 °C and extracted several times with ether. The combined extracts were dried over Na2SO4, concentrated in vacuum and purified on SiO2 column to give 1b (110 mg, 58%).